Ambler Campus, Temple University

This month we will discuss the larger evergreen hollies that are grown as trees or large shrubs. Next month we will discuss the smaller evergreen hollies that can provide great winter structure in the garden.

Our native evergreen American Holly, Ilex opaca, (PHS Gold Medal Plant 2001), can grow to about 45’, but is most often seen as a smaller tree, as it grows quite slowly. The female produces red berries (or drupes) that are attractive to birds. My large tree may sometimes hold many of the berries until early spring when one day a huge flock of robins descends and with much flapping and twittering proceeds to strip the berries off the tree.

The May/ June flowers are small, white and insignificant but have a very sweet, haunting fragrance that wafts on the breeze. As with the deciduous hollies, do remember that to set fruit there must be a male holly nearby. If you have a small garden and there are other hollies in your neighborhood you may be fine. Often people do not know where the male holly is that is pollinating their female plant. One way to find out if you need to add a male is just to plant and see if you get berries.

There are many cultivars and selections of American Holly to choose from. Many that are available are unnamed, but it is worth seeking a known cultivar that maybe has better foliage or fruit set. The leaf of American Hollies is a dull green in color, and some of the cultivars have better looking leaves.

Suggested cultivars that you may find are ‘Old Heavy Berry,’ Miss Helen, and Jersey Princess. If you prefer yellow berries look for Ilex opaca xanthocarpa. One of the best American Hollies, on campus is to be seen at the top of the hill on the student walkway from the parking lot, opposite Cottage Hall.

The English Holly, Ilex aquifolium, is also evergreen. The main difference between this holly and its American cousin is that it has a more glossy leaf. Again the female has usually red berries and needs a pollinator. This is slightly less cold hardy, so in Zone 6 plant in a sheltered position. There are many cultivars available including the much desired variegated leaf varieties (often sold just as Ilex aquifolium ‘Variegata’) that are cut and used for indoor decorations and arrangements. In Europe, holly was brought into the house at this time of year to ward off evil during the 12 days of Christmas.

Evergreen hollies will grow in shade or sun, but are more full, lush, and berried with
more sun. They will grow in a variety of different soils as long as they are not waterlogged. Some protection from excessive wind is necessary to prevent winter damage
to the foliage. Hollies do seem to be able to tolerate some urban air pollution. I would also suggest planting a small holly rather than a larger one. Hollies resent root disturbance and take some time to recover from transplanting once established. Small holly plants are also good for making a formal or informal hedge.

Hedges are pruned in August to allow the berries to remain on the plant, and to allow the setting of the buds for next year’s flowers. Evergreen hollies can be pruned as
a simple topiary; most common forms would be a lollipop or a pyramid. If pruning trees
or large shrubs, December is a great time because the cuttings can be used to make a holly and mixed evergreen wreath, or to decorate the mantelpiece and table. A British custom is to put a sprig of holly on top of Plum pudding (also known as Christmas pudding, made with dried fruit). The holly is taken off before the pudding is doused with brandy and set alight!

Pests and diseases on evergreen hollies are minimal. The leaves may be disfigured by the tunneling of the holly leaf miner (caused by an insect related to flies) that burrows between the upper and lower leaf surfaces. These disfigured leaves can be picked off and thrown in the trash. Deer do not seem to prefer to eat the evergreen hollies, but I have had problems this year with rabbits gnawing at the lower limbs. I have fenced in the base of the plant with a ring of chicken wire until the holly grows.

Other evergreen holly hybrids that you may want to consider for your garden include:

Ilex ‘Nellie R. Stevens’: See this holly behind the Administration Building. This is a commonly available holly that will grow to a small tree in size. It is widely grown as it is self fertile and will bear orange red colored berries even without a male pollinator. If clipped, Nellie will provide a dense screen.

Ilex ‘Oakleaf’: Oakleaf may be found in the Arboretum in the Albright Winter Garden by the upper path. This holly is one of the relatively new Red Hybrid Hollies. This holly has large leaves that resemble an oak leaf. The form of the plant will be a tall pyramid about eight feet wide.

Ilex x ‘Lydia Morris’: This type is situated behind the Administration Building. Look for a holly with very spiny foliage and leaves tightly clustered along the stems. This holly is named after Lydia Morris who was, with her brother John Morris, the owner of the estate in Chestnut Hill that is now the Morris Arboretum.

Have a very happy holiday season! Come and walk around and see our wonderful hollies. Evergreen hollies look even better with a coating of snow. Watch for more holly information next month.